Ipad 2 WiFi Problem after replacing WiFi Flex

Occasionally our shop breaks a wifi antenna on an ipad when removing the broken glass. We have a stock of wifi antennas to replace. We do about 1,000 ipad repairs a year and very rarely break an antenna. One of my techs recently just broke one and replaced it. Problem is that the wifi reception even with the new one is not good at all.

Do we just have crap replacement antennas? or am I missing something simple